Arch anatomy often goes undocumented on preoperative imaging, yet children undergoing extended end-to-end repair with bovine arch anatomy are at a significantly increased risk of recoarctation. This may be due to a reduced clampable distance to facilitate repair. These results should be considered in the preoperative assessment, parental counseling, and surgical approach for children with discrete aortic coarctation.

Background Marfan syndrome (MFS) represents a genetic disorder with variable phenotypic expression. The main cardiovascular sequelae of MFS include aortic aneurysm/dissection and cardiomyopathy. While significant advances in the understanding of TGF-β signaling have led to promising therapeutic targets for the treatment of aortopathy, clinical studies have tempered this optimism. In particular, these studies suggest additional signaling pathways that play a significant role in disease progression. To date, studies aimed at elucidating molecular mechanisms involved in MFS -induced disease progression have been hampered by the lack of an accelerated disease model. Methods B6.129 (Wild-type) and Fbn1C1039G/+ (MFS) mice underwent subcutaneous, cervical osmotic mini-pump installation with either sodium chloride (in Wild-type mice, n=20; in MFS mice, n=7) or angiotensin II (4.5mg/kg/day) (in MFS mice; n=15) for up to 28 days. Interval measurements of mouse hemodynamics were obtained throughout the experiment. Aortas and hearts were analyzed by transthoracic echocardiography and histopathology. Results This accelerated murine MFS model replicates increased mortality from MFS-related maladies (63% at 28 days versus 0% for non-accelerated MFS mice). Aortic diameters in accelerated MFS mice were significantly enlarged at 10 days after mini-pump implantation and correlated with a higher degree of elastin fragmentation. Accelerated MFS mice also demonstrated dilated cardiomyopathy at 14 days, even without aortic insufficiency, suggesting an intrinsic etiology. Conclusion A novel in vivo model consisting of subcutaneously delivered angiotensin II in MFS mice reproducibly causes accelerated aortic aneurysm formation and cardiomyopathy. This model allows for better investigation of the sequelae of MFS via rapid experimental processes.

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